With the success of Guy Ritchie's "Sherlock Holmes" and the fact that Holmes' iconic nemesis Prof. Moriarty was talked about but never really shown, all eyes were on the sequel and the eventual debut of the classic villain. Who could possibly hope to match wits with Robert Downey Jr's eccentric genius sleuth in "Sherlock Holmes: A Game of Shawdows"?

Enter Harris – best known for playing “Mad Men’s” resident Brit Lane Pryce – as the new “Napoleon of crime." The veteran actor (and son of the late Richard Harris) sat down with PopcornBiz to talk about how he hopes to prove that Holmes isn't always the smartest guy in the room.

This version of 'Sherlock Holmes' is always kind of a little bit left of center from the original.

They’re left of center. Yeah. Well, I liked that it was my role! That's what I liked best about it. I loved the first movie, so I was excited to be in it and be a part of it. And all the things that worked in the first one, they're all there, and they're more intense in this one.

What did you like about working against Robert, who’s everybody's actor's actor right now.

Yeah - he's very, very generous, and he's very inventive. He inspires you and challenges you to be as inventive and just to give everything that you've got. And also, he's very courageous, as well. He's not afraid of trying on an idea and it not working, you know what I mean? He's not a safe actor at all. So in a way it inspires it, a level of risk taking and daredevil-ness amongst the rest of the cast.

Did you take a look at any of the past Moriartys from the prior Holmes films at all?

Yeah, I looked at them. We looked at them a little bit. And I'm not tall enough for the original idea of the character: He was six foot two, he was older and he had the sort of stooped, hunched over look, slightly resembling a bird of something like that. So we had to change it a bit. But really mostly it was the effect of the character that you were trying to get across. And that is a sort of overriding sense of menace and someone who's just behind everything. And he's a sort of grand master chess player: he's 17 moves ahead.

Is there anything you can say about the upcoming season of “Mad Men” without bringing down the wrath of Matthew Wiener?

I think people will be very, very pleased – it's going to be worth the wait. The scripts are fantastic. His inventiveness and the quality of the writing and his attention for the detail and for character and characterization, everything – It's really, really great. I love that even the scripts that you're not in, you want to get home and read them. There's some of the best reading that you get.

How was Jon Hamm as a director?

He's good. He did a great job. I mean, the best direction is always brief. If you're having to explain what you want to an actor and it takes you two minutes you can't remember all that. It was very specific, so that’s what you want.

"Sherlock Holmes: A Game of Shadows" opens everywhere Friday, December 16th